Methods of synthesizing cyclic nitro compounds

ABSTRACT

The present invention provides cyclic nitro compounds, pharmaceutical compositions of cyclic nitro compounds and methods of using cyclic nitro compounds and/or pharmaceutical compositions thereof to treat or prevent diseases or disorders characterized by abnormal cell proliferation, such as cancer, inflammation, cardiovascular disease and autoimmune disease.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/252,278, filed Oct. 15, 2008, now U.S. Pat. No. 7,745,643, issuedJun. 29, 2010, which application is a divisional of U.S. patentapplication Ser. No. 11/502,810, filed Aug. 11, 2006, now U.S. Pat. No.7,507,842, issued Mar. 24, 2009, which application claims priority toU.S. Provisional Application No. 60/707,851, filed Aug. 12, 2005. Thisapplication is also related to U.S. patent application Ser. No.12/397,651, filed Mar. 4, 2009, pending, which is a continuation of U.S.patent application Ser. No. 11/502,810, filed Aug. 11, 2006, now U.S.Pat. No. 7,507,842, issued Mar. 24, 2009. The disclosure of each of theabove-mentioned patent applications and patents is hereby incorporatedherein by this reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to pharmaceutical compositionsof cyclic nitro compounds and methods of using cyclic nitro compoundsand pharmaceutical compositions thereof to treat or prevent diseasescharacterized by abnormal cell proliferation, such as cancer.

BACKGROUND OF THE INVENTION

Abnormal cell proliferation is a characteristic symptom of cancer.Further, abnormal cell proliferation has been implicated in numerousother diseases (e.g., cardiovascular diseases, inflammatory diseasessuch as rheumatoid arthritis, diabetic retinopathy, etc.). Although manymethods for treating or preventing aberrant cell proliferation have beendeveloped, a significant problem with most existing therapies isselectively distinguishing between normal and abnormal cellproliferation.

Radiotherapy is one promising approach to selectively targeting abnormalcell proliferation. A number of different radiosensitizers have beendescribed in the art and include thiols, nitroimidazoles and metaltexaphyrin compounds (see, e.g., Rosenthal et al., Clin. Cancer. Res.,1999, 739). Significant problems with existing radiosensitizationapproaches are (1) the formation of toxic byproducts derived from theradiosensitizers, which has limited their usefulness in cancer therapy;and (2) achieving sufficiently high density of free radicals to beefficacious under dose limiting toxicity.

Another popular approach to selectively targeting abnormal cellproliferation is treatment with bioreductive compounds, which areselectively activated in a reducing environment. Since many cancerstypically contain regions of low oxygen tension (i.e., hypoxia),compounds with low redox potentials (i.e., bioreductive compounds) maybe selectively activated in the reducing environment of tumor cellswithout external activation.

Accordingly, new compounds are required to fully explore treating orpreventing abnormal cell proliferation. These new compounds may haveradiotherapeutic activity or bioreductive activity. Such compounds maybe effective in treating or preventing various diseases associated withabnormal cell proliferation, such as cancer, without forming toxicbyproducts.

SUMMARY OF THE INVENTION

The present invention satisfies this and other needs by providing cyclicnitro compounds, pharmaceutical compositions of cyclic nitro compoundsand methods of using cyclic nitro compounds or pharmaceuticalcompositions thereof to treat or prevent diseases associated withabnormal cell proliferation.

In a first aspect, a compound of structural Formula (I):

or salts, solvates or hydrates thereof is provided wherein:

R¹, R², R³ and R⁴ are each independently, hydrogen, alkyl, substitutedalkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, heteroarylalkyl, substituted heteroarylalkyl, halo, hydroxyor nitro;

each R⁵ and R⁶ are each independently, hydrogen, alkyl, substitutedalkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, heteroarylalkyl, substituted heteroarylalkyl, halo, hydroxyor nitro;

-   -   O is 0, 1, 2, 3 or 4;

R⁷ is substituted alkyl, substituted arylalkyl, substituted heteroalkyl,substituted heteroaryl, substituted heteroarylalkyl, substituted acyl,substituted alkoxycarbonyl, substituted phosphonyl or substitutedsulfonyl;

provided that at least one of R¹, R², R³, R⁴, R⁵ and R⁶ are nitro.

In a second aspect, methods for treating or preventing diseases ordisorders characterized by abnormal cell proliferation are provided. Themethods generally involve administering to a patient in need of suchtreatment or prevention a therapeutically effective amount of a cyclicnitro compound or a pharmaceutically acceptable salt, hydrate, solvateor N-oxide thereof.

In a third aspect, pharmaceutical compositions of cyclic nitro compoundsare provided. The pharmaceutical compositions generally comprise one ormore cyclic nitro compounds, pharmaceutically acceptable salts,hydrates, solvates or N-oxides thereof and a pharmaceutically acceptablevehicle. The choice of vehicle will depend upon, among other factors,the desired mode of administration.

In a fourth aspect, pharmaceutical compositions for treating orpreventing diseases or disorders characterized by abnormal cellproliferation are provided. The methods generally involve administeringto a patient in need of such treatment or prevention a therapeuticallyeffective amount of a pharmaceutical composition comprising a cyclicnitro compound or a pharmaceutically acceptable salt, hydrate, solvateor N-oxide thereof and a pharmaceutically acceptable vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the dose and cell line dependency of ROS productionin tumor cells in the presence of ABDNAZ;

FIG. 2 illustrates ROS production in HT29 tumor cells in the presence ofirradiated ABDNAZ;

FIG. 3 illustrates ROS production in SCC VII tumor cells in the presenceof irradiated ABDNAZ;

FIG. 4 illustrates inhibition of proliferation of bcl-2 and vectortransfected HL60 cells by ABDNAZ;

FIG. 5 illustrates induction of apoptosis of bcl-2 and vectortransfected HL60 cells by ABDNAZ;

FIG. 6 illustrates the apoptosis and cell cycle profile of HL60 neocells after exposure to ABDNAZ;

FIG. 7 illustrates the apoptosis and cell cycle profile of HL60 bc1-2cells after exposure to ABDNAZ; and

FIG. 8 illustrates the inhibition of bcl-2 expression in HL60 cells.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Definitions

“Alkyl” by itself or as part of another substituent refers to asaturated or unsaturated, branched, straight-chain or cyclic monovalenthydrocarbon radical derived by the removal of one hydrogen atom from asingle carbon atom of a parent alkane, alkene or alkyne. Typical alkylgroups include, but are not limited to, methyl; ethyls such as ethanyl,ethenyl, ethynyl; propyls such as propan-1-yl, propan-2-yl,cyclopropan-1-yl, prop-1-en-1-yl, prop-1-en-2-yl, prop-2-en-1-yl(allyl), cycloprop-1-en-1-yl; cycloprop-2-en-1-yl, prop-1-yn-1-yl,prop-2-yn-1-yl, etc.; butyls such as butan-1-yl, butan-2-yl,2-methyl-propan-1-yl, 2-methyl-propan-2-yl, cyclobutan-1-yl,but-1-en-1-yl, but-1-en-2-yl, 2-methyl-prop-1-en-1-yl, but-2-en-1-yl,but-2-en-2-yl, buta-1,3-dien-1-yl, buta-1,3-dien-2-yl,cyclobut-1-en-1-yl, cyclobut-1-en-3-yl, cyclobuta-1,3-dien-1-yl,but-1-yn-1-yl, but-1-yn-3-yl, but-3-yn-1-yl, etc.; and the like.

The term “alkyl” is specifically intended to include groups having anydegree or level of saturation, i.e., groups having exclusively singlecarbon-carbon bonds, groups having one or more double carbon-carbonbonds, groups having one or more triple carbon-carbon bonds and groupshaving mixtures of single, double and triple carbon-carbon bonds. Wherea specific level of saturation is intended, the expressions “alkanyl,”“alkenyl,” and “alkynyl” are used. In some embodiments, an alkyl groupcomprises from 1 to 20 carbon atoms. In other embodiments, an alkylgroup comprises 1 to 10 carbon atoms. In still other embodiments, analkyl group comprises from 1 to 6 carbon atoms.

“Alkanyl” by itself or as part of another substituent refers to asaturated branched, straight-chain or cyclic alkyl radical derived bythe removal of one hydrogen atom from a single carbon atom of a parentalkane. Typical alkanyl groups include, but are not limited to,methanyl; ethanyl; propanyls such as propan-1-yl, propan-2-yl(isopropyl), cyclopropan-1-yl, etc.; butanyls such as butan-1-yl,butan-2-yl (sec-butyl), 2-methyl-propan-1-yl (isobutyl),2-methyl-propan-2-yl (t-butyl), cyclobutan-1-yl, etc.; and the like.

“Alkenyl” by itself or as part of another substituent refers to anunsaturated branched, straight-chain or cyclic alkyl radical having atleast one carbon-carbon double bond derived by the removal of onehydrogen atom from a single carbon atom of a parent alkene. The groupmay be in either the cis or trans conformation about the double bond(s).Typical alkenyl groups include, but are not limited to, ethenyl;propenyls such as prop-1-en-1-yl, prop-1-en-2-yl, prop-2-en-1-yl(allyl), prop-2-en-2-yl, cycloprop-1-en-1-yl; cycloprop-2-en-1-yl;butenyls such as but-1-en-1-yl, but-1-en-2-yl, 2-methyl-prop-1-en-1-yl,but-2-en-1-yl, but-2-en-2-yl, buta-1,3-dien-1-yl, buta-1,3-dien-2-yl,cyclobut-1-en-1-yl, cyclobut-1-en-3-yl, cyclobuta-1,3-dien-1-yl, etc.;and the like.

“Alkynyl” by itself or as part of another substituent refers to anunsaturated branched, straight-chain or cyclic alkyl radical having atleast one carbon-carbon triple bond derived by the removal of onehydrogen atom from a single carbon atom of a parent alkyne. Typicalalkynyl groups include, but are not limited to, ethynyl; propynyls suchas prop-1-yn-1-yl, prop-2-yn-1-yl, etc.; butynyls such as but-1-yn-1-yl,but-1-yn-3-yl, but-3-yn-1-yl, etc.; and the like.

“Acyl” by itself or as part of another substituent refers to a radical—C(O)R³⁰, where R³⁰ is hydrogen, alkyl, cycloalkyl, cycloheteroalkyl,aryl, arylalkyl, heteroalkyl, heteroaryl, heteroarylalkyl as definedherein. Representative examples include, but are not limited to, formyl,acetyl, cyclohexylcarbonyl, cyclohexylmethylcarbonyl, benzoyl,benzylcarbonyl, and the like.

“Alkoxycarbonyl” by itself or as part of another substituent refers to aradical —C(O)OR³¹ where R³¹ represents an alkyl or cycloalkyl group asdefined herein. Representative examples include, but are not limited to,methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl,cyclohexyloxycarbonyl and the like.

“Aryl” by itself or as part of another substituent refers to amonovalent aromatic hydrocarbon group derived by the removal of onehydrogen atom from a single carbon atom of a parent aromatic ringsystem. Typical aryl groups include, but are not limited to, groupsderived from aceanthrylene, acenaphthylene, acephenanthrylene,anthracene, azulene, benzene, chrysene, coronene, fluoranthene,fluorene, hexacene, hexaphene, hexylene, as-indacene, s-indacene,indane, indene, naphthalene, octacene, octaphene, octalene, ovalene,penta-2,4-diene, pentacene, pentalene, pentaphene, perylene, phenalene,phenanthrene, picene, pleiadene, pyrene, pyranthrene, rubicene,triphenylene, trinaphthalene, and the like. In some embodiments, an arylgroup comprises from 6 to 20 carbon atoms. In other embodiments, an arylgroup comprises from between 6 to 12 carbon atoms.

“Arylalkyl” by itself or as part of another substituent refers to anacyclic alkyl group in which one of the hydrogen atoms bonded to acarbon atom, typically a terminal or sp³ carbon atom, is replaced withan aryl group. Typical arylalkyl groups include, but are not limited to,benzyl, 2-phenylethan-1-yl, 2-phenylethen-1-yl, naphthylmethyl,2-naphthylethan-1-yl, naphthobenzyl, 2-naphthophenylethan-1-yl, and thelike. Where specific alkyl moieties are intended, the nomenclaturearylalkanyl, arylalkenyl and/or arylalkynyl is used. In someembodiments, an arylalkyl group is (C₆-C₃₀) arylalkyl, e.g., thealkanyl, alkenyl or alkynyl moiety of the arylalkyl group is (C₁-C₁₀)and the aryl moiety is (C₆-C₂₀). In other embodiments, an arylalkylgroup is (C₆-C₂₀) arylalkyl, e.g., the alkanyl, alkenyl or alkynylmoiety of the arylalkyl group is (C₁-C₈) and the aryl moiety is(C₆-C₁₂).

“Heteroalkyl, Heteroalkanyl, Heteroalkenyl and Heteroalkynyl” bythemselves or as part of another substituent refer to alkyl, alkanyl,alkenyl and alkynyl groups, respectively, in which one or more of thecarbon atoms (and any associated hydrogen atoms) are independentlyreplaced with the same or different heteroatomic groups. Typicalheteroatomic groups which can be included in these groups include, butare not limited to, —O—, —S—, —O—O—, —S—S—, —O—S—, —NR³⁴R³⁵—, ═N—N═,N═N—, —N═NR³⁶R³⁷, —PR³⁸—, —P(O)₂—, —POR³⁹—, —O—P(O)₂—, —SO—, —SO₂—,—SNR⁴⁰R⁴¹—, and the like, where R³⁴, R³⁵, R³⁶, R³⁷, R³⁸, R³⁹, R⁴⁰, andR⁴¹ are independently hydrogen, alkyl, substituted alkyl, aryl,substituted aryl, arylalkyl, substituted arylalkyl, cycloalkyl,substituted cycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, heteroarylalkyl or substituted heteroarylalkyl.

“Heteroaryl” by itself or as part of another substituent refers to amonovalent heteroaromatic radical derived by the removal of one hydrogenatom from a single atom of a parent heteroaromatic ring system. Typicalheteroaryl groups include, but are not limited to, groups derived fromacridine, arsindole, carbazole, β-carboline, chromane, chromene,cinnoline, furan, imidazole, indazole, indole, indoline, indolizine,isobenzofuran, isochromene, isoindole, isoindoline, isoquinoline,isothiazole, isoxazole, naphthyridine, oxadiazole, oxazole, perimidine,phenanthridine, phenanthroline, phenazine, phthalazine, pteridine,purine, pyran, pyrazine, pyrazole, pyridazine, pyridine, pyrimidine,pyrrole, pyrrolizine, quinazoline, quinoline, quinolizine, quinoxaline,tetrazole, thiadiazole, thiazole, thiophene, triazole, xanthene, and thelike. In some embodiments, the heteroaryl group is between 5-20 memberedheteroaryl. In other embodiments, the heteroaryl group is between 5-10membered heteroaryl. In some embodiments, heteroaryl groups includethose derived from thiophene, pyrrole, benzothiophene, benzofuran,indole, pyridine, quinoline, imidazole, oxazole and pyrazine.

“Heteroarylalkyl” by itself or as part of another substituent refers toan acyclic alkyl group in which one of the hydrogen atoms bonded to acarbon atom, typically a terminal or sp³ carbon atom, is replaced with aheteroaryl group. Where specific alkyl moieties are intended, thenomenclature heteroarylalkanyl, heteroarylalkenyl and/orheteroarylalkynyl is used. In some embodiments, the heteroarylalkylgroup is a 6-30 membered heteroarylalkyl, e.g., the alkanyl, alkenyl oralkynyl moiety of the heteroarylalkyl is 1-10 membered and theheteroaryl moiety is a 5-20 membered heteroaryl. In other embodiments,the heteroarylalkyl group is a 6-20 membered heteroarylalkyl, e.g., thealkanyl, alkenyl or alkynyl moiety of the heteroarylalkyl is 1-8membered and the heteroaryl moiety is a 5-12 membered heteroaryl.

“Parent Aromatic Ring System” by itself or as part of anothersubstituent refers to an unsaturated cyclic or polycyclic ring systemhaving a conjugated π electron system. Specifically included within thedefinition of “parent aromatic ring system” are fused ring systems inwhich one or more of the rings are aromatic and one or more of the ringsare saturated or unsaturated, such as, for example, fluorene, indane,indene, phenalene, etc. Typical parent aromatic ring systems include,but are not limited to, aceanthrylene, acenaphthylene,acephenanthrylene, anthracene, azulene, benzene, chrysene, coronene,fluoranthene, fluorene, hexacene, hexaphene, hexylene, as-indacene,s-indacene, indane, indene, naphthalene, octacene, octaphene, octacene,ovalene, penta-2,4-diene, pentacene, pentalene, pentaphene, perylene,phenalene, phenanthrene, picene, pleiadene, pyrene, pyranthrene,rubicene, triphenylene, trinaphthalene, and the like.

“Parent Heteroaromatic Ring System” by itself or as part of anothersubstituent, refers to a parent aromatic ring system in which one ormore carbon atoms (and any associated hydrogen atoms) are independentlyreplaced with the same or different heteroatom. Typical heteroatoms toreplace the carbon atoms include, but are not limited to, N, P, O, S,Si, etc. Specifically included within the definition of “parentheteroaromatic ring systems” are fused ring systems in which one or moreof the rings are aromatic and one or more of the rings are saturated orunsaturated, such as, for example, arsindole, benzodioxan, benzofuran,chromane, chromene, indole, indoline, xanthene, etc. Typical parentheteroaromatic ring systems include, but are not limited to, arsindole,carbazole, β-carboline, chromane, chromene, cinnoline, furan, imidazole,indazole, indole, indoline, indolizine, isobenzofuran, isochromene,isoindole, isoindoline, isoquinoline, isothiazole, isoxazole,naphthyridine, oxadiazole, oxazole, perimidine, phenanthridine,phenanthroline, phenazine, phthalazine, pteridine, purine, pyran,pyrazine, pyrazole, pyridazine, pyridine, pyrimidine, pyrrole,pyrrolizine, quinazoline, quinoline, quinolizine, quinoxaline,tetrazole, thiadiazole, thiazole, thiophene, triazole, xanthene, and thelike.

“Pharmaceutically acceptable salt” refers to a salt of a cyclic nitrocompound, which is pharmaceutically acceptable and possesses the desiredpharmacological activity of the parent compound. Such salts include: (1)acid addition salts, formed with inorganic acids such as hydrochloricacid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid andthe like; or formed with organic acids such as acetic acid, propionicacid, hexanoic acid, cyclopentanepropionic acid, glycolic acid, pyruvicacid, lactic acid, malonic acid, succinic acid, malic acid, maleic acid,fumaric acid, tartaric acid, citric acid, benzoic acid,3-(4-hydroxybenzoyl)benzoic acid, cinnamic acid, mandelic acid,methanesulfonic acid, ethanesulfonic acid, 1,2-ethane-disulfonic acid,2-hydroxyethanesulfonic acid, benzenesulfonic acid,4-chlorobenzenesulfonic acid, 2-naphthalenesulfonic acid,4-toluenesulfonic acid, camphorsulfonic acid,4-methylbicyclo[2.2.2]-oct-2-ene-1-carboxylic acid, glucoheptonic acid,3-phenylpropionic acid, trimethylacetic acid, t-butylacetic acid, laurylsulfuric acid, gluconic acid, glutamic acid, hydroxynaphthoic acid,salicylic acid, stearic acid, muconic acid and the like or (2) saltsformed when an acidic proton present in the parent compound is replacedby an ammonium ion, a metal ion, e.g., an alkali metal ion (e.g., sodiumor potassium), an alkaline earth ion (e.g., calcium or magnesium), or analuminum ion; or coordinates with an organic base such as ethanolamine,diethanolamine, triethanolamine, N-methylglucamine, morpholine,piperidine, dimethylamine, diethylamine, and the like. Also included aresalts of amino acids such as arginates and the like, and salts oforganic acids like glucurmic or galactunoric acids and the like.

“Pharmaceutically acceptable vehicle” refers to a diluent, adjuvant,excipient or carrier with which a cyclic nitro compound is administered.

“Patient” includes humans and other mammals.

“Phosphonyl” by itself or as part of another substituent refers to aradical —P(O)(OR³²)₂, where each R³² is independently hydrogen, alkyl,cycloalkyl, cycloheteroalkyl, aryl, arylalkyl, heteroalkyl, heteroaryl,heteroarylalkyl as defined herein.

“Preventing” or “prevention” refers to a reduction in risk of acquiringa disease or disorder (i.e., causing at least one of the clinicalsymptoms of the disease not to develop in a patient that may be exposedto or predisposed to the disease but does not yet experience or displaysymptoms of the disease).

“Substituted” refers to a group in which one or more hydrogen atoms areindependently replaced with the same or different substituent(s).Typical substituents include, but are not limited to, -M, —R⁶⁰, —O⁻, ═O,—OR⁶⁰, —SR⁶⁰, —S⁻, ═S, NR⁶⁰R⁶¹, ═NR⁶⁰, —CF₃, —CN, —OCN, —SCN, —NO, —NO₂,—ONO₂, ═N₂, —N₃, —S(O)₂O⁻, —S(O)₂OH, —S(O)₂R⁶⁰, —OS(O₂)O⁻, —OS(O)₂R⁶⁰,—P(O)(O⁻)₂, —P(O)(OR⁶⁰)(O⁻), —OP(O)OR⁶⁰)(OR⁶¹), —C(O)R⁶⁰, —C(S)R⁶⁰,—C(O)OR⁶⁰, —C(O)NR⁶⁰R⁶¹, —C(O)O⁻, —C(S)OR⁶⁰, —NR⁶²C(O)NR⁶⁰R⁶¹,—NR⁶²C(S)NR⁶⁰R⁶¹, —NR⁶²C(NR⁶³)NR⁶⁰R⁶¹ and —C(NR⁶²)NR⁶⁰R⁶¹ where M isindependently a halogen; R⁶⁰, R⁶¹, R⁶² and R⁶³ are independentlyhydrogen, alkyl, substituted alkyl, alkoxy, substituted alkoxy,cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substitutedcycloheteroalkyl, aryl, substituted aryl, heteroaryl or substitutedheteroaryl, or, optionally, R⁶⁰ and R⁶¹, together with the nitrogen atomto which they are bonded, form a cycloheteroalkyl or substitutedcycloheteroalkyl ring; and R⁶⁴ and R⁶⁵ are independently hydrogen,alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl,cycloheteroalkyl, substituted cycloheteroalkyl, aryl, substituted aryl,heteroaryl or substituted heteroaryl, or, optionally, R⁶⁴ and R⁶⁵together with the nitrogen atom to which they are bonded, form acycloheteroalkyl or substituted cycloheteroalkyl ring. In someembodiments, substituents include -M, —R⁶⁰, ═O, —OR⁶⁰, —SR⁶⁰, —S⁻, ═S,—NR⁶⁰R⁶¹, ═NR⁶⁰, —CF₃, —CN, —OCN, —SCN, —NO, —NO₂, —ONO₂, ═N₂, —N₃,—S(O)₂R⁶⁰, —OS(O₂)O⁻, OS(O)₂R⁶⁰, —P(O)(O⁻)₂, —P(O)(OR⁶⁰)(O⁻),—OP(O)(OR⁶⁰)(OR⁶¹), —C(O)R⁶⁰, —C(S)R⁶⁰, —C(O)OR⁶⁰, —C(O)NR⁶⁰R⁶¹,—C(O)O⁻, —NR⁶²C(O)NR⁶⁰R⁶¹, where R⁶⁰, R⁶¹ and R⁶² are as defined above.In other embodiments, substituents include -M, —R⁶⁰, ═O, —OR⁶⁰, —SR⁶⁰,—NR⁶⁰R⁶¹, —CF₃, —CN, —NO₂, —ONO₂, —S(O)₂R⁶⁰, —P(O)(OR⁶⁰)(O⁻),—OP(O)(OR⁶⁰)(OR⁶¹), —C(O)R⁶⁰, —C(O)OR⁶⁰, —C(O)NR⁶⁰R⁶¹ and —C(O)O⁻ whereR⁶⁰, R⁶¹ and R⁶² are as defined above. In still other embodiments,substituents include -M, —R⁶⁰, ═O, —OR⁶⁰, —SR⁶⁰, —NR⁶⁰R⁶¹, —CF₃, —CN,—NO₂, —ONO₂, —S(O)₂R⁶⁰, —OP(O)(OR⁶⁰)(OR⁶¹), —C(O)R⁶⁰, —C(O)OR⁶⁰ and—C(O)O⁻, where R⁶⁰, R⁶¹ and R⁶² are as defined above.

“Sulfonyl” by itself or as part of another substituent refers to aradical —S(O)₂R₃₃, where each R³³ is independently hydrogen, alkyl,cycloalkyl, cycloheteroalkyl, aryl, arylalkyl, heteroalkyl, heteroaryl,heteroarylalkyl as defined herein.

“Treating” or “treatment” of any disease or disorder refers, in oneembodiment, to ameliorating the disease or disorder (i.e., arresting orreducing the development of the disease or at least one of the clinicalsymptoms thereof). In another embodiment, “treating” or “treatment”refers to ameliorating at least one physical parameter, which may not bediscernible by the patient. In yet another embodiment, “treating” or“treatment” refers to inhibiting the disease or disorder, eitherphysically, (e.g., stabilization or eradication of a discerniblesymptom), physiologically, (e.g., stabilization or eradication of aphysical parameter) or both. In yet another embodiment, “treating” or“treatment” refers to delaying the onset of the disease or disorder.

“Therapeutically effective amount” means the amount of a compound that,when administered to a patient for treating or preventing a disease, issufficient to effect such treatment or prevention of the disease. The“therapeutically effective amount” will vary depending on the compound,the disease and its severity and the age, weight, etc., of the patientto be treated.

Reference will now be made in detail to embodiments of the invention.While the invention will be described in conjunction with theseembodiments, it will be understood that it is not intended to limit theinvention to those preferred embodiments. To the contrary, it isintended to cover alternatives, modifications, and equivalents as may beincluded within the spirit and scope of the invention as defined by theappended claims.

Cyclic Nitro Compounds and their Use to Treat or Prevent Abnormal CellProliferation

The present invention provides cyclic nitro compounds, pharmaceuticalcompositions of cyclic nitro compounds and methods of using cyclic nitrocompounds or pharmaceutical compositions thereof to treat or preventdiseases associated with abnormal cell proliferation.

The methods generally involve administering to a patient in need of suchtreatment or prevention a therapeutically effective amount of a cyclicnitro compound or a pharmaceutically acceptable salt, hydrate, solvateor N-oxide thereof. In one embodiment, the cyclic nitro compound isintracellularly activated by the reducing environment of a tumor cell.In another embodiment, the patient is irradiated to activate the cyclicnitro compound. Without wishing to be bound by theory, irradiation orreduction of cyclic nitro compounds may lead to formation of freeradicals that subsequently prevent cell replication and kill cells,presumably by interfering with DNA replication and/or reacting with cellmembranes. However, other mechanisms, presently unknown, may account forthe efficacy of cyclic nitro compounds in treating or preventingabnormal cell proliferation.

Accordingly, in some embodiments, the cyclic nitro compounds of thepresent invention may be activated by both intracellular reduction andexternal irradiation. In these embodiments, a synergistic or additiveeffect may be observed.

Cyclic nitro compounds are generally organic compounds substituted withone or more nitro groups (i.e., nitro compounds) but also includenitrate salts (e.g., ammonium dinitride, aluminum trinitride, etc.).Typically, cyclic nitro compounds have a high enthalpy of formation(i.e., decomposition of cyclic nitro compounds releases a high amount ofenergy). In some embodiments, cyclic nitro compounds have an enthalpy offormation that varies between about 5 kcal/mole and about 150 kcal/mole,more preferably, between about 10 kcal/mole and about 110 kcal/mole. Theenthalpy of formation of nitro compounds may be readily calculated bymethods known to the skilled artisan. Accordingly, cyclic nitrocompounds include those nitro compounds that decompose with explosiveforce upon activation. Such compounds may be readily identified by thoseof skill in the art by calculation of the enthalpy of formation.

Cyclic nitro compounds may also be reduced at low reduction potentials.Cyclic voltammetry demonstrates that electron transfer to cyclic nitrocompounds occurs between about −0.1 volt and about −1.0 volt usingstandard electrodes (e.g., mercury or carbon cathode and platinum anode)and electrolyte solutions.

In some embodiments, cyclic nitro compounds contain a high density ofnitro groups (i.e., the nitro groups represent a significant fraction ofthe overall mass of the compound). In other embodiments, cyclic nitrocompounds contain two nitro groups. In still other embodiments, cyclicnitro compounds contain three nitro groups. In still other embodiments,cyclic nitro compounds contain three or more nitro groups. In stillother embodiments, a cyclic nitro compound contains six nitro groups.

In some embodiments, the cyclic nitro compound is a nitrocarbon whichhas a ratio of nitro groups to carbon atoms of 1:1. In otherembodiments, the cyclic nitro compound is a nitrocarbon which has aratio of nitro groups to carbon atoms of 1:2.

In some embodiments, a compound of structural Formula (I):

or salts, solvates or hydrates thereof is provided wherein:

R¹, R², R³ and R⁴ are each independently, hydrogen, alkyl, substitutedalkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, heteroarylalkyl, substituted heteroarylalkyl, halo, hydroxyor nitro;

each R⁵ and R⁶ are each independently, hydrogen, alkyl, substitutedalkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, heteroarylalkyl, substituted heteroarylalkyl, halo, hydroxyor nitro;

-   -   O is 0, 1, 2, 3 or 4;

R⁷ is substituted alkyl, substituted arylalkyl, substituted heteroalkyl,substituted heteroaryl, substituted heteroarylalkyl, substituted acyl,substituted alkoxycarbonyl, substituted phosphonyl or substitutedsulfonyl;

provided that at least one of R¹, R², R³, R⁴, R⁵ and R⁶ are nitro.

In some embodiments, at least two of R¹, R², R³, R⁴, R⁵ or R⁶ are nitro.In other embodiments, R¹, R², R³ and R⁴ are each independently,hydrogen, alkyl or nitro and each R⁵ and R⁶ are each independently,hydrogen, alkyl or nitro. In still other embodiments, R⁷ is substitutedalkyl, substituted acyl, substituted alkoxycarbonyl, substitutedphosphonyl or substituted sulfonyl. In still other embodiments, R⁷ isalkyl, acyl, alkoxycarbonyl, phosphonyl or sulfonyl substituted with oneor more halogen, —CF₃ or —OS(O)₂R⁸, wherein R⁸ is alkyl, substitutedalkyl, aryl or substituted aryl. In still other embodiments, R³ and R⁴are nitro.

In some embodiments, R,¹R², R³ and R⁴ are each independently, hydrogen,alkyl or nitro, each R⁵ and R⁶ are each independently, hydrogen, alkylor nitro and R⁷ is substituted alkyl, substituted acyl, substitutedalkoxycarbonyl, substituted phosphonyl or substituted sulfonyl. In otherembodiments, R¹, R², R³ and R⁴ are each independently, hydrogen, alkylor nitro, each R⁵ and R⁶ are each independently, hydrogen, alkyl ornitro and R⁷ is alkyl, acyl, alkoxycarbonyl, phosphonyl or sulfonylsubstituted with one or more halogen, —CF₃ or —OS(O)₂R⁸, wherein R⁸ isalkyl, substituted alkyl, aryl or substituted aryl. In still otherembodiments, R¹ and R² are each independently, hydrogen, alkyl or nitro,R³ and R⁴ are nitro, each R⁵ and R⁶ are each independently, hydrogen,alkyl or nitro, R⁷ is substituted alkyl, substituted acyl, substitutedalkoxycarbonyl, substituted phosphonyl or substituted sulfonyl. In stillother embodiments, R¹ and R² are each independently, hydrogen, alkyl ornitro, R³ and R⁴ are nitro, each R⁵ and R⁶ are each independently,hydrogen, alkyl or nitro, R⁷ is alkyl, acyl, alkoxycarbonyl, phosphonylor sulfonyl substituted with one or more halogen, —CF₃ or —OS(O)₂R⁸,wherein R⁸ is alkyl, substituted alkyl, aryl or substituted aryl. Insome of any of the above embodiments, O is 1.

In some embodiments, R¹ and R² are each independently, hydrogen, alkylor nitro, R³ and R⁴ are nitro, R⁵ and R⁶ are each independently,hydrogen, alkyl or nitro, R⁷ is alkyl or acyl substituted with one ormore halogens or —CF₃ and O is 1. In other embodiments, R¹ and R² arehydrogen, R³ and R⁴ are nitro, R⁵ and R⁶ are hydrogen, R⁷ is alkyl oracyl substituted with one or more halogen or —CF₃ and O is 1.

In some embodiments, the cyclic nitro compound has the structure:

wherein each X is independently —F, —Cl, —Br, —I or —OS(O)₂R⁸ where R⁸is methyl, CF₃, phenyl or tolyl and each p is independently 1, 2, 3, or4.

In other embodiments, the cyclic nitro compound has the structure:

wherein each X is independently —F, —Cl, —Br, —I, —OS(O)₂R⁸ where R⁸ ismethyl, CF₃, phenyl or tolyl. In some specific embodiments, the cyclicnitro compound has the structure:

commonly referred to as ABDNAZ.

Cyclic nitro compounds may exist in several tautomeric forms andmixtures thereof. Cyclic nitro compounds may also include isotopicallylabeled compounds where one or more atoms have an atomic mass differentfrom the atomic mass conventionally found in nature. Examples ofisotopes that may be incorporated into cyclic nitro compounds include,but are not limited to, ²H, ³H, ¹³C, ¹⁴C, ¹⁵N, ¹⁸O and ¹⁷O. Cyclic nitrocompounds may exist in unsolvated forms as well as solvated forms,including hydrated forms or N-oxides. In general, hydrated and solvatedforms are within the scope of the present invention. Certain cyclicnitro compounds may exist in multiple crystalline or amorphous forms. Ingeneral, all physical forms are equivalent for the uses contemplated bythe present invention and are intended to be within the scope of thepresent invention.

Cyclic nitro compounds may be activated by intracellular reduction. Insome embodiments, cyclic nitro compounds are activated by intracellularreduction in hypoxic tumor cells, secondary to elevated glutathionelevels (high GSH:GSSG (i.e., glutathione to glutathione disulfideratios)) and possibly high levels of other antioxidant enzymes in manytumor cells and/or a median tumor cell pO₂ of less than about 10 mm Hg.

Cyclic nitro compounds may also be activated by application of externalenergy. Methods useful for decomposing cyclic nitro compounds include,but are not limited to, irradiation (e.g., with X-rays, visible light,infrared irradiation) ultrasound (e.g., focused ultrasound),electrochemical reduction, heating, co-administration of free radicalinitiators (e.g., thiols), etc. In some embodiments, a cyclic nitrocompound is activated by photon irradiation of the patient. In someembodiments, the patient's tumor is irradiated using a linearaccelerator at a dose rate of about 100 cGy/min. The patient may also betreated with electron beam therapy, interoperative radiation therapy,stereostatic radiosurgery and high or low dose brachytherapy.

In some situations the entire patient may be irradiated. In someembodiments, a portion of the patient is irradiated so that only cyclicnitro compound localized in the irradiated portion (e.g., tumor region)of the patient is activated. Preferably, the portion of the patientwhich is irradiated is the site of abnormal cell proliferation.

Cyclic nitro compounds may be obtained via conventional syntheticmethods described in the art or are commercially available, e.g., fromATK Thiokol, Salt Lake City, Utah. Starting materials useful forpreparing cyclic nitro compounds and intermediates thereof arecommercially available or can be prepared by well-known syntheticmethods. Other methods for synthesis of the cyclic nitro compoundsdescribed herein and/or starting materials are either described in theart or will be readily apparent to the skilled artisan.

In accordance with the invention, a cyclic nitro compound or apharmaceutical composition thereof is administered to a patient,preferably a human, suffering from a disease characterized by abnormalcell proliferation. The cyclic nitro compound and pharmaceuticalcompositions thereof may be used to treat or prevent diseasescharacterized by abnormal cell proliferation.

Diseases characterized by abnormal cell proliferation include, but arenot limited to, cancer (e.g., any vascularized tumor, preferably, asolid tumor, including but not limited to, carcinomas of the lung,breast, ovary, stomach, pancreas, larynx, esophagus, testes, liver,parotid, biliary tract, colon, rectum, cervix, uterus, endometrium,kidney, bladder, prostrate, thyroid, squamous cell carcinomas,adenocarcinomas, small cell carcinomas, melanomas, gliomas,neuroblastomas, sarcomas (e.g., angiosarcomas, chondrosarcomas)),diabetes, cardiovascular diseases (e.g., arteriosclerosis), inflammatorydiseases (e.g., arthritis, diabetic retinopathy, rheumatoid arthritis,neovascular glaucoma and psoriasis) and autoimmune diseases.

In other embodiments, cyclic nitro compounds may be used for in-vitrosterilization. Biological solutions may be treated with cyclic nitrocompounds, which are toxic to pathogenic bacteria, viruses and cells.This process can also be catalyzed by the application of external energysuch as light and heat.

Further, in certain embodiments, a cyclic nitro compound and/orpharmaceutical composition thereof is administered to a patient,preferably a human, as a preventative measure against various diseasesor disorders characterized by abnormal cell proliferation. Thus, cyclicnitro compounds and/or pharmaceutical compositions thereof may beadministered as a preventative measure to a patient having apredisposition for a disease characterized by abnormal cellproliferation. Accordingly, cyclic nitro compounds and/or pharmaceuticalcompositions thereof may be used for the prevention of one disease ordisorder and concurrently treating another (e.g., preventing arthritiswhile treating cancer).

Therapeutic/prophylactic Administration

Cyclic nitro compounds and/or pharmaceutical compositions thereof may beadvantageously used in human medicine. As previously describedhereinabove, cyclic nitro compounds and/or pharmaceutical compositionsthereof are useful for the treatment or prevention of various diseasesor disorders such as those listed above.

When used to treat or prevent the above diseases or disorders, cyclicnitro compounds and/or pharmaceutical compositions thereof may beadministered or applied singly, or in combination with other agents.Cyclic nitro compounds and/or pharmaceutical compositions thereof mayalso be administered or applied singly, or in combination with otherpharmaceutically active agents (e.g., other anti-cancer agents, otherarthritis agents, etc.), including other cyclic nitro compounds and/orpharmaceutical compositions thereof.

The current invention provides methods of treatment and prophylaxis byadministration to a patient of a therapeutically effective amount of acyclic nitro compound and/or pharmaceutical composition thereof. Thepatient is preferably, a mammal and most preferably, is a human.

Cyclic nitro compounds and/or pharmaceutical compositions thereof may beadministered orally. Cyclic nitro compounds and/or pharmaceuticalcompositions thereof may also be administered by any other convenientroute, for example, by infusion or bolus injection, by absorptionthrough epithelial or mucocutaneous linings (e.g., oral mucosa, rectaland intestinal mucosa, etc.). Administration can be systemic or local.Various delivery systems are known, (e.g., encapsulation in liposomes,microparticles, microcapsules, capsules, etc.) that can be used toadminister a cyclic nitro compound and/or pharmaceutical compositionthereof. Methods of administration include, but are not limited to,intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous,intranasal, epidural, oral, sublingual, intranasal, intracerebral,intravaginal, transdermal, rectally, by inhalation, or topically,particularly to the ears, nose, eyes or skin. The mode of administrationis left to the discretion of the practitioner, and will depend in-partupon the site of the medical condition. In most instances,administration will result in the release of cyclic nitro compoundsand/or pharmaceutical compositions thereof into the bloodstream.

In specific embodiments, it may be desirable to administer one or morecyclic nitro compounds and/or pharmaceutical compositions thereoflocally to the area in need of treatment. This may be achieved, forexample, and not by way of limitation, by local infusion during surgery,topical application, e.g., in conjunction with a wound dressing aftersurgery, by injection, by means of a catheter, by means of asuppository, or by means of an implant, the implant being of a porous,non-porous, or gelatinous material, including membranes, such asSILASTIC® membranes or fibers. In one embodiment, administration can beby direct injection at the site (or former site) of the disease ordisorder.

In certain embodiments, it may be desirable to introduce one or morecyclic nitro compounds and/or pharmaceutical compositions thereof intothe central nervous system by any suitable route, includingintraventricular, intrathecal and epidural injection. Intraventricularinjection may be facilitated by an intraventricular catheter, forexample, attached to a reservoir, such as an Ommaya reservoir.

Cyclic nitro compounds and/or pharmaceutical compositions thereof mayalso be administered directly to the lung by inhalation. Foradministration by inhalation, cyclic nitro compounds and/orpharmaceutical compositions thereof may be conveniently delivered to thelung by a number of different devices. For example, a Metered DoseInhaler (“MDI”), which utilizes canisters that contain a suitable lowboiling propellant, (e.g., dichlorodifluoromethane,trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or anyother suitable gas) may be used to deliver cyclic nitro compounds and/orpharmaceutical compositions thereof directly to the lung.

Alternatively, a Dry Powder Inhaler (“DPI”) device may be used toadminister a cyclic nitro compound and/or pharmaceutical compositionthereof to the lung. DPI devices typically use a mechanism such as aburst of gas to create a cloud of dry powder inside a container, whichmay then be inhaled by the patient and are well known in the art. Apopular variation is the multiple dose DPI (“MDDPI”) system, whichallows for the delivery of more than one therapeutic dose. MDDPI devicesare commercially available from a number of pharmaceutical companies(e.g., Schering Plough, Madison, N.J.). For example, capsules andcartridges of gelatin for use in an inhaler or insufflator may beformulated containing a powder mix of a cyclic nitro compound and/orpharmaceutical composition thereof and a suitable powder base such aslactose or starch for these systems.

Another type of device that may be used to deliver a cyclic nitrocompound and/or pharmaceutical composition thereof to the lung is aliquid spray device supplied, for example, by Aradigm Corporation,Hayward, Calif. Liquid spray systems use extremely small nozzle holes toaerosolize liquid drug formulations that may then be directly inhaledinto the lung.

In some embodiments, a nebulizer is used to deliver a cyclic nitrocompound and/or pharmaceutical composition thereof to the lung.Nebulizers create aerosols from liquid drug formulations by using, forexample, ultrasonic energy to form fine particles that may be readilyinhaled (see, e.g., Raleigh et al., British J. Cancer, 1999, 80, Suppl.2, 96). Examples of nebulizers include devices supplied by SheffieldPharmaceuticals, St. Louis, Mo. (Armer et al., U.S. Pat. No. 5,954,047;van der Linden et al., U.S. Pat. No. 5,950,619; van der Linden et al.,U.S. Pat. No. 5,970,974), and Batelle Pulmonary Therapeutics, Columbus,Ohio.

In other embodiments, an electrohydrodynamic (“EHD”) aerosol device isused to deliver a cyclic nitro compound and/or pharmaceuticalcomposition thereof to the lung of a patient. EHD aerosol devices useelectrical energy to aerosolize liquid drug solutions or suspensions(see, e.g., Noakes et al., U.S. Pat. No. 4,765,539). The electrochemicalproperties of the formulation may be important parameters to optimizewhen delivering a cyclic nitro compound and/or pharmaceuticalcomposition thereof to the lung with an EHD aerosol device and suchoptimization is routinely performed by one of skill in the art. EHDaerosol devices may more efficiently deliver drugs to the lung thanexisting pulmonary delivery technologies.

In some embodiments, a cyclic nitro compound and/or pharmaceuticalcompositions thereof can be delivered in a vesicle, in particular aliposome (e.g., Langer, 1990, Science, 249:1527-1533; Treat et al., in“Liposomes in the Therapy of Infectious Disease and Cancer,”Lopez-Berestein and Fidler (eds.), Liss, New York, pp. 353-365 (1989)).

In some embodiments, a cyclic nitro compound and/or pharmaceuticalcompositions thereof can be delivered via sustained release systems,preferably oral sustained release systems. In other embodiments, a pumpmay be used (e.g., Langer, supra, Sefton, 1987, CRC Crit. Ref. Biomed.Eng. 14:201; Sauder et al., 1989, N. Engl. J. Med. 321:574).

In some embodiments, polymeric materials can be used (e.g., “MedicalApplications of Controlled Release,” Langer and Wise (eds.), CRC Press,Boca Raton, Fla. (1974); “Controlled Drug Bioavailability,” Drug ProductDesign and Performance, Smolen and Ball (eds.), Wiley, New York (1984);Langer et al., 1983, J. Macromol. Sci. Rev. Macromol. Chem. 23:61; Levyet al., 1985, Science 228:190; During et al., 1989, Ann. Neurol. 25:351;Howard et al., 1989, J. Neurosurg. 71:105).

In other embodiments, polymeric materials are used for oral sustainedrelease delivery. Polymers include, but are not limited to, sodiumcarboxymethylcellulose, hydroxypropylcellulose,hydroxypropylmethylcellulose and hydroxyethylcellulose (most preferred,hydroxypropyl methylcellulose). Other cellulose ethers have beendescribed (Alderman, Int. J. Pharm. Tech. & Prod. Mfr. 1984, 5(3) 1-9).Factors affecting drug release are well known to the skilled artisan andhave been described in the art (Bamba et al., Int. J. Pharm. 1979, 2,307).

In other embodiments, enteric-coated preparations can be used for oralsustained release administration. Coating materials include polymerswith a pH-dependent solubility (i.e., pH-controlled release), polymerswith a slow or pH-dependent rate of swelling, dissolution or erosion(i.e., time-controlled release), polymers that are degraded by enzymes(i.e., enzyme-controlled release) and polymers that form firm layersthat are destroyed by an increase in pressure (i.e., pressure-controlledrelease).

In other embodiments, osmotic delivery systems are used for oralsustained release administration (Verma et al., Drug Dev. Ind. Pharm.,2000, 26:695-708). In some embodiments, OROS® osmotic devices are usedfor oral sustained release delivery devices (Theeuwes et al., U.S. Pat.No. 3,845,770; Theeuwes et al., U.S. Pat. No. 3,916,899).

In yet other embodiments, a controlled-release system can be placed inproximity of the target of the cyclic nitro compound and/orpharmaceutical composition, thus requiring only a fraction of thesystemic dose (e.g., Goodson, in “Medical Applications of ControlledRelease,” supra, vol. 2, pp. 115-138 (1984)). Other controlled-releasesystems previously may also be used (Langer, 1990, Science249:1527-1533).

Pharmaceutical Compositions

The present pharmaceutical compositions typically contain atherapeutically effective amount of one or more cyclic nitro compounds,preferably, in purified form, together with a suitable amount of apharmaceutically acceptable vehicle, so as to provide the form forproper administration to a patient. When administered to a patient, thecyclic nitro compound and pharmaceutically acceptable vehicles arepreferably sterile. Water is a preferred vehicle when the cyclic nitrocompound is administered intravenously. Saline solutions and aqueousdextrose and glycerol solutions can also be employed as liquid vehicles,particularly for injectable solutions. Suitable pharmaceutical vehiclesalso include excipients such as starch, glucose, lactose, sucrose,gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerolmonostearate, talc, sodium chloride, dried skim milk, glycerol,propylene, glycol, water, ethanol, and the like. The presentpharmaceutical compositions, if desired, can also contain minor amountsof wetting or emulsifying agents, or pH buffering agents. In addition,auxiliary, stabilizing, thickening, lubricating and coloring agents maybe used.

Pharmaceutical compositions comprising a cyclic nitro compound may bemanufactured by means of conventional mixing, dissolving, granulating,dragee-making, levigating, emulsifying, encapsulating, entrapping orlyophilizing processes. Pharmaceutical compositions may be formulated inconventional manner using one or more physiologically acceptablecarriers, diluents, excipients or auxiliaries, which facilitateprocessing of compounds into preparations which can be usedpharmaceutically. Proper formulation is dependent upon the route ofadministration chosen.

The present pharmaceutical compositions can take the form of solutions,suspensions, emulsions, tablets, pills, pellets, capsules, capsulescontaining liquids, powders, sustained-release formulations,suppositories, aerosols, sprays, or any other form suitable for use. Inone embodiment, the pharmaceutically acceptable vehicle is a capsule(e.g., Grosswald et al., U.S. Pat. No. 5,698,155). A general discussionof the preparation of pharmaceutical compositions may be found inRemington, “The Science and Practice of Pharmacy,” 19^(th) Edition.

For topical administration, a cyclic nitro compound may be formulated assolutions, gels, ointments, creams, suspensions, etc., as is well knownin the art.

Systemic formulations include those designed for administration byinjection, e.g., subcutaneous, intravenous, intramuscular, intrathecalor intraperitoneal injection, as well as those designed for transdermal,transmucosal, oral or pulmonary administration. Systemic formulationsmay be made in combination with a further active agent that improvesmucociliary clearance of airway mucus or reduces mucous viscosity. Theseactive agents include, but are not limited to, sodium channel blockers,antibiotics, N-acetyl cysteine, homocysteine and phospholipids.

In a preferred embodiment, cyclic nitro compounds are formulated inaccordance with routine procedures as a pharmaceutical compositionadapted for intravenous administration to human beings. Typically,cyclic nitro compounds are solutions in sterile isotonic aqueous bufferfor intravenous administration. For injection, cyclic nitro compoundsmay be formulated in aqueous solutions, preferably in physiologicallycompatible buffers such as Hanks' solution, Ringer's solution, orphysiological saline buffer. The solution may contain formulatory agentssuch as suspending, stabilizing and/or dispersing agents. Whennecessary, the pharmaceutical compositions may also include asolubilizing agent. Pharmaceutical compositions for intravenousadministration may optionally include a local anesthetic such aslignocaine to ease pain at the site of the injection. Generally, theingredients are supplied either separately or mixed together in unitdosage form, for example, as a lyophilized powder or water freeconcentrate in a hermetically sealed container such as an ampoule orsachette indicating the quantity of active agent. When the cyclic nitrocompounds are administered by infusion, the cyclic nitro compounds canbe dispensed, for example, with an infusion bottle containing sterilepharmaceutical grade water or saline. When the cyclic nitro compound isadministered by injection, an ampoule of sterile water for injection orsaline can be provided so that the ingredients may be mixed prior toadministration.

For transmucosal administration, penetrants appropriate to the barrierto be permeated are used in the formulation. Such penetrants aregenerally known in the art.

Pharmaceutical compositions for oral delivery may be in the form oftablets, lozenges, aqueous or oily suspensions, granules, powders,emulsions, capsules, syrups, or elixirs, for example. Orallyadministered pharmaceutical compositions may contain one or moreoptional agents, for example, sweetening agents such as fructose,aspartame or saccharin; flavoring agents such as peppermint, oil ofwintergreen, or cherry coloring agents and preserving agents, to providea pharmaceutically palatable preparation. Moreover, when in tablet orpill form, the pharmaceutical compositions may be coated to delaydisintegration and absorption in the gastrointestinal tract, therebyproviding a sustained action over an extended period of time.Selectively permeable membranes surrounding an osmotically activedriving compound are also suitable for orally administered compounds. Inthese latter platforms, fluid from the environment surrounding thecapsule is imbibed by the driving compound, which swells to displace theagent or agent composition through an aperture. These delivery platformscan provide an essentially zero order delivery profile as opposed to thespiked profiles of immediate release formulations. A time delay materialsuch as glycerol monostearate or glycerol stearate may also be used.Oral compositions can include standard vehicles such as mannitol,lactose, starch, magnesium stearate, sodium saccharine, cellulose,magnesium carbonate, etc. Such vehicles are preferably of pharmaceuticalgrade.

For oral liquid preparations such as, for example, suspensions, elixirsand solutions, suitable carriers, excipients or diluents include water,saline, alkyleneglycols (e.g., propylene glycol), polyalkylene glycols(e.g., polyethylene glycol) oils, alcohols, slightly acidic buffersbetween pH 4 and pH 6 (e.g., acetate, citrate, ascorbate at betweenabout 5.0 mM to about 50.0 mM), etc. Additionally, flavoring agents,preservatives, coloring agents, bile salts, acylcarnitines, and thelike, may be added.

For buccal administration, the pharmaceutical compositions may take theform of tablets, lozenges, etc., formulated in conventional manner.

Liquid drug formulations suitable for use with nebulizers and liquidspray devices and EHD aerosol devices typically include a cyclic nitrocompound with a pharmaceutically acceptable vehicle. Preferably, thepharmaceutically acceptable vehicle is a liquid such as alcohol, water,polyethylene glycol or a perfluorocarbon. Optionally, another materialmay be added to alter the aerosol properties of the solution orsuspension of compounds. Preferably, this material is liquid such as analcohol, glycol, polyglycol or a fatty acid. Other methods offormulating liquid drug solutions or suspensions suitable for use inaerosol devices are known to those of skill in the art (see, e.g.,Biesalski, U.S. Pat. No. 5,112,598; Biesalski, U.S. Pat. No. 5,556,611).

A cyclic nitro compound may also be formulated in rectal or vaginalpharmaceutical compositions such as suppositories or retention enemas,e.g., containing conventional suppository bases such as cocoa butter orother glycerides.

In addition to the formulations described previously, a cyclic nitrocompound may also be formulated as a depot preparation. Such long actingformulations may be administered by implantation (for example,subcutaneously or intramuscularly) or by intramuscular injection. Thus,for example, a cyclic nitro compound may be formulated with suitablepolymeric or hydrophobic materials (e.g., as an emulsion in anacceptable oil) or ion exchange resins, or as sparingly solublederivatives, such as a sparingly soluble salt.

When a cyclic nitro compound is acidic or basic, it may be included inany of the above-described formulations as the free acid or free base, apharmaceutically acceptable salt, a solvate or hydrate. Pharmaceuticallyacceptable salts substantially retain the activity of the free acid orbase, may be prepared by reaction with bases or acids and tend to bemore soluble in aqueous and other protic solvents than the correspondingfree acid or base form.

Doses

A cyclic nitro compound and/or pharmaceutical composition thereof willgenerally be used in an amount effective to achieve the intendedpurpose. For the use to treat or prevent the above diseases ordisorders, the cyclic nitro compound and/or pharmaceutical compositionsthereof are administered or applied in a therapeutically effectiveamount.

The amount of a cyclic nitro compound and/or pharmaceutical compositionthereof that will be effective in the treatment of a particular disorderor condition disclosed herein will depend on the nature of the disorderor condition, and can be determined by standard clinical techniquesknown in the art. In addition, in vitro or in vivo assays may optionallybe employed to help identify optimal dosage ranges. The amount of acyclic nitro compound and/or pharmaceutical composition thereofadministered will, of course, be dependent on, among other factors, thesubject being treated, the weight of the subject, the severity of theaffliction, the manner of administration and the judgment of theprescribing physician.

For example, the dosage may be delivered in a pharmaceutical compositionby a single administration, by multiple applications or controlledrelease. Dosing may be repeated intermittently, may be provided alone orin combination with other drugs and may continue as long as required foreffective treatment of the disease state or disorder.

Suitable dosage ranges for oral administration are dependent on theefficiency of radiosensitization, but are generally about 0.001 mg toabout 100 mg of the cyclic nitro compound per kg body weight. Dosageranges may be readily determined by methods known to the artisan ofordinary skill.

Suitable dosage ranges for intravenous (i.v.) administration are about0.01 mg to about 100 mg per kg/body weight. Suitable dosage ranges forintranasal administration are generally about 0.01 mg/kg body weight toabout 1 mg/kg body weight. Suppositories generally contain about 0.01milligram to about 50 milligrams of a cyclic nitro compound per kg/bodyweight and comprise active ingredient in the range of about 0.5% toabout 10% by weight. Recommended dosages for intradermal, intramuscular,intraperitoneal, subcutaneous, epidural, sublingual or intracerebraladministration are in the range of about 0.001 mg to about 200 mg per kgbody weight. Effective doses may be extrapolated from dose-responsecurves derived from in vitro or animal model test systems. Such animalmodels and test systems are well known in the art.

The cyclic nitro compounds are preferably assayed in vitro and in vivo,for the desired therapeutic or prophylactic activity, prior to use inhumans. For example, in vitro assays can be used to determine whetheradministration of a specific cyclic nitro compound or a combination ofcyclic nitro compounds is preferred. The cyclic nitro compound may alsobe demonstrated to be effective and safe using animal model testsystems.

Preferably, a therapeutically effective dose of a cyclic nitro compoundand/or pharmaceutical composition thereof described herein will providetherapeutic benefit without causing substantial toxicity. Toxicity ofcyclic nitro compounds and/or pharmaceutical compositions thereof may bedetermined using standard pharmaceutical procedures and may be readilyascertained by the skilled artisan. The dose ratio between toxic andtherapeutic effect is the therapeutic index. A cyclic nitro compoundand/or pharmaceutical composition thereof will preferably exhibitparticularly high therapeutic indices in treating diseases and disorderscharacterized by aberrant abnormal cell proliferation. The dosage of acyclic nitro compound and/or pharmaceutical composition thereofdescribed herein will preferably be within a range of circulatingconcentrations that include an effective dose with little or notoxicity.

Combination Therapy

In certain embodiments of the present invention, cyclic nitro compoundsand/or pharmaceutical compositions thereof can be used in combinationtherapy with at least one other therapeutic agent. The cyclic nitrocompound and/or pharmaceutical composition thereof and the therapeuticagent can act additively or, more preferably, synergistically. In oneembodiment, a cyclic nitro compound and/or a pharmaceutical compositionthereof is administered concurrently with the administration of anothertherapeutic agent. In another embodiment, a cyclic nitro compound and/orpharmaceutical composition thereof is administered prior or subsequentto administration of another therapeutic agent.

In particular, in one embodiment, cyclic nitro compounds and/orpharmaceutical compositions thereof can be used in combination therapywith other chemotherapeutic agents (e.g., alkylating agents (e.g.,nitrogen mustards (e.g., cyclophosphamide, ifosfamide, mechlorethamine,melphalen, chlorambucil, hexamethylmelamine, thiotepa), alkyl sulfonates(e.g., busulfan), nitrosoureas, triazines)), antimetabolites (e.g.,folic acid analogs, pyrimidine analogs (e.g., fluorouracil, floxuridine,cytosine arabinoside, etc.)), purine analogs (e.g., mercaptopurine,thioguanine, pentostatin, etc.), natural products (e.g., vinblastine,vincristine, etoposide, tertiposide, dactinomycin, daunorubicin,doxurubicin, bleomycin, mithromycin, mitomycin C, L-asparaginase,interferon alpha), platinum coordination complexes (e.g., cis-platinum,carboplatin, etc.), apoptosis-inducing agents, glutathione-depletingagents or other agents that can alter the redox status of the cell.Those of skill in the art will appreciate that cyclic nitro compoundsmay also be used in concurrent combination therapy with both thechemotherapeutic agents listed above and radiotherapy.

Therapeutic Kits

The current invention also provides therapeutic kits comprising cyclicnitro compounds and/or pharmaceutical compositions thereof. Thetherapeutic kits may also contain other compounds (e.g.,chemotherapeutic agents, natural products, apoptosis-inducing agents,etc.) or pharmaceutical compositions thereof.

Therapeutic kits may have a single container that contains a cyclicnitro compound and/or pharmaceutical composition thereof with or withoutother components (e.g., other compounds or pharmaceutical compositionsof these other compounds) or may have a distinct container for eachcomponent. Preferably, therapeutic kits include a cyclic nitro compoundand/or a pharmaceutical composition thereof packaged for use incombination with the co-administration of a second compound (preferably,a chemotherapeutic agent, a natural product, an apoptosis-inducingagent, etc.) or a pharmaceutical composition thereof. The components ofthe kit may be pre-complexed or each component may be in a separatedistinct container prior to administration to a patient.

The components of the kit may be provided in one or more liquidsolutions, preferably, an aqueous solution, more preferably, a sterileaqueous solution. The components of the kit may also be provided assolids, which may be converted into liquids by addition of suitablesolvents, which are preferably provided in another distinct container.

The container of a therapeutic kit may be a vial, test tube, flask,bottle, syringe, or any other means of enclosing a solid or liquid.Usually, when there is more than one component, the kit will contain asecond vial or other container, which allows for separate dosing. Thekit may also contain another container for a pharmaceutically acceptableliquid.

Preferably, a therapeutic kit will contain apparatus (e.g., one or moreneedles, syringes, eye droppers, pipettes, etc.), which enablesadministration of the components of the kit.

EXAMPLES

The invention is further defined by reference to the following examples,which describe in detail, preparation of compounds and methods forassaying for biological activity. It will be apparent to those skilledin the art that many modifications, both to materials and methods, maybe practiced without departing from the scope.

Example 1 Production of ROS in Tumor

Cells by ABDNAZ and Irradiation

Human colon cancer cell line HT29 cells and murine squamous cellcarcinoma cell line SCC VII cells were grown in 96-well plates overnightat 37° C. and then a fluorescent probe 2′7′-dichlorofluorescin diacetate(DCFH-DA) was added at a concentration of 20 μm for 1 hour and thenwashed out. ABDNAZ was added in the growth media at concentrations of 1μM, 10 μM or 100 μM. The green fluorescence was observed under afluorescence microscope and measured using a microplatespectrofluorometer with an excitation at 488 nm and an emission at 525nm. For cells that were treated with both ABDNAZ and irradiation, theplates were irradiated immediately after addition of ABDNAZ using a¹³⁷Cs source.

FIG. 1 shows the production of reactive oxygen species (ROS) in HT29cells and SCC VII cells after exposure to ABDNAZ. The production of ROSwas dose, time and cell line dependent. The ROS production in HT29 cellswas gradually increased over time and peaked at 24 hours. For SCC VIIcells, the production of ROS peaked 2 hours after addition of ABDNAZ,and the levels of ROS were significantly higher than that induced inHT29 cells.

FIGS. 2 and 3 illustrate the ROS production in HT29 cells and SCC VIIcells, respectively, treated with ABDNAZ and radiation. Combinedtreatment of ABDNAZ and radiation synergistically induced intracellularROS generation in HT29 cells and SCC VII cells, as compared with eachmodality alone.

Example 2 Inhibition of Proliferation of HL60 Cells by ABDNAZ

The HL60 cell line, which is an acute promyelocytic leukemia cell line,was stably transfected with bcl-2 oncogene (HL60 bcl-2 cells). The HL60neo cells were used as a control (HL60 neo). Cells were grown inRPMI1640 media in the presence of ABDNAZ at a concentration of 1 μM, 2μM or 5 μM. The number of viable cells was counted daily for ten days.The cell growth curves are shown in FIG. 4, which demonstrates thatABDNAZ inhibited cell growth in a dose-dependent manner. A dose of 5 μMof ABDNAZ inhibited cell growth by >95% and HL60 bcl-2 cells were assensitive as neo cells to ABDNAZ.

Example 3 Induction of Apoptosis of HL60 Cells by ABDNAZ

Cells, prepared and grown as described in Example 2, supra, werecollected at 8, 24, 48, and 72 hours after addition of ABDNAZ, andanalyzed using FACS. FIG. 5 illustrates the percent of apoptosis vs.time in the presence of ABDNAZ. As can be seen in FIGS. 5, 6 and 7,ABDNAZ induced a very high level of apoptotic cell death in both HL60neo and bcl-2 cells in a dose-dependent manner. ABDNAZ at 5 μM induced95% and 78% apoptosis at 48 hours for neo and bcl-2 cells, respectively.At 2 μM, ABDNAZ produced apoptotic cell death that was very similar inHL60 neo and bcl-2 cells with peaks of ˜40% at 8 hours. FIGS. 6 and 7illustrate the detailed histograms of FACS analysis for HL60 neo cellsand HL60 bcl-2 cells, respectively.

Example 4 Inhibition of bcl-2 Oncogene Expression by ABDNAZ

HL60 cells were treated as described in Example 2, supra. Cells werecollected at 6 and 24 hours for Western blot analysis. As shown in FIG.8, ABDNAZ at 2 and 5 μM inhibited bcl-2 protein expression in both neoand bcl-2 cells in a dose-dependent manner. The bcl-2 protein in HL60bcl-2-transfected cells may be cleaved in the presence of 2 μM ABDNAZ asindicated by the presence of the lower molecular weight bands after both6 and 24 hours.

Example 5 Synthesis of ABDNAZ

A 25 ml, three-neck, round-bottomed flask was charged with 7 ml ofmethylene chloride and 2.50 g (12.3 mmol) of t-BuDNAZ prepared asdescribed in Archibald et al., Journal of Organic Chemistry, 1990, 2920.Under nitrogen, 0.16 ml (1.23 mmol) of boron trifluoride etherate wasadded. After stirring 5 minutes at ambient temperature, 0.54 ml (6.15mol) of bromoacetyl bromide was added. The solution was heated between50-60° C. for 2 hours. The darkened reaction mixture was cooled toambient temperature, diluted with 50 ml methylene chloride, andfiltered. The solid was identified as the HBr salt of t-BuDNAZ. Themethylene chloride filtrate was washed with two 20 ml portions of water,dried over sodium sulfate, filtered, and evaporated under reducedpressure. The resultant solid was washed with three 20 ml portions ofethyl ether and dried under vacuum to yield 1.24 g (75.2% based onbromoacetyl bromide) of BrADNAZ as a white solid (mp=124-125° C.). ¹HNMR (CDCl₃): δ 3.76 (s, 2H), 4.88 (br s, 2H), 5.14 (br s, 2H); ¹³C NMR(CDCl₃): δ 165.2, 105.0, 59.72, 57.79, 23.90. Calc. for C₅H₆BrN₃O₅: % C,22.41; % H, 2.26; % N, 15.68. Found: % C, 22.61; % H, 2.36; % N, 15.58.HPLC/MS C-8 reverse phase column with acetonitrile/water mobilephase—m/e 266.95 (100%), 268.95 (98.3%). FTIR: 3014.24 (weak), 1677.66,1586.30, 1567.65, 1445.55 (NO₂), 1367.80, 1338.00, 1251.27 cm⁻¹.

Example 6 Synthesis of N-(chloroacetyl)-3,3-dinitroazetidine (ClADNAZ)

A 25 ml, three-neck, round-bottomed flask was charged with 7 ml ofmethylene chloride and 2.50 g (12.3 mmol) of t-BuDNAZ. Under nitrogen,0.16 ml (1.23 mmol) of boron trifluoride etherate was added. Afterstirring 5 minutes at ambient temperature, 0.54 ml (6.15 mol) ofchloroacetyl chloride was added. The solution was heated between 50-60°C. for 2 hours. The darkened reaction mixture was cooled to ambienttemperature, diluted with 50 ml methylene chloride and filtered. Thesolid was identified as the HCl salt of t-BuDNAZ. The methylene chloridefiltrate was washed with two 20 ml portions of water, dried over sodiumsulfate, filtered, and evaporated under reduced pressure. The resultantsolid was washed with three 20 ml portions of ethyl ether and driedunder vacuum to afford a white solid (mp: 130-132° C.) in 60% yield. CHNfor C₅H₆ClN₃O₅. Found C, 26.94%; H, 2.53%; N, 17.77%. Calculated C,26.86%; H, 2.71%; N, 18.79%. FTIR: 2979 (weak), 1690.01, 1577.57,1438.91 (NO₂), 1368.21, 1338.99, 1286.21 cm⁻¹. ¹H NMR: (DMSO-d₆), δ 5.09(2H), 4.81 (2H), 3.77 (2H). ¹³C NMR: (DMSO-d₆), δ 168.58, 106.98, 60.39,50.38. HPLC: >98% pure. Safety Data: ABL Impact: 80 cm; ABL Friction:800 at 8 ft/sec; TC ESD Unconfined at 50%: 1.10 Joules (mass ignition onbulk test). DSC Onset: 259.56° C.

Example 7 Synthesis of N-Iodoacetyl-3,3-dinitroazetidine (IADNAZ)

A 100 ml, three-neck, round-bottomed flask was charged with 40 mL ofanhydrous acetone and 2.01 g of BrADNAZ under nitrogen. 1.4 g K₂CO₃ wasadded followed by the addition of 1.2 g sodium iodide. The reactionmixture was allowed to reflux overnight and monitored by proton NMR. Thedarkened solution was diluted with methylene chloride, the solid wasfiltered and the filtrate was extracted with 2×30 mL portions ofmethylene chloride and water. The organic layer was dried over sodiumsulfate and concentrated under vacuum. The solid was purified by flashcolumn chromatography (10% ethyl acetate/hexanes) to yield a white solid(mp: 97-100° C.) in 80% yield. Analysis for C₅H₆IN₃O₅. Found C, 19.67%;H, 1.80%; N, 12.70%. Calculated C, 19.06%; H, 1.92%; N, 13.24%. FTIR:2980 (weak), 1667.44, 1568.49, 1439.74 (NO₂), 1373.69, 1335.60, 1305.35cm⁻¹. ¹H NMR: (DMSO-d₆), δ 5.09 (2H), 4.81 (2H), 3.77 (2H). ¹³C NMR:(DMSO-d₆), δ 168.58, 106.98, 60.39, 50.38. HPLC: >98% pure. Safety Data:ABL Impact: 80 cm; ABL Friction: 800 at 8 ft/sec; TC ESD, Unconfined 50%7.30 Joules (no mass ignition on bulk test); SBAT Onset: 286° F. DSCOnset: 253.52° C.

Example 8 Synthesis of N-Azidoacetyl-3,3-dinitroazetidine (AzADNAZ)

A 100 ml, three-neck flack was charged with 40 mL of anhydrous acetoneand 2.01 g of BrADNAZ under nitrogen. 1.05 g K₂CO₃ was added followed bythe addition of 0.4 g sodium azide. The reaction mixture was allowed toreflux overnight and monitored by proton NMR. The darkened solution wasdiluted with methylene chloride and the solid was filtered. The filtratewas extracted with two 30 mL portions of methylene chloride and water.The organic layer was dried over sodium sulfate and concentrated undervacuum. The solid was purified by flash column chromatography (10% ethylacetate/hexanes) to yield a white solid (mp: 103-104° C.) in 80% yield.Analysis for C₅H₆N₆O₅. Found C, 26.84%; H, 2.70%; N, 35.49%. CalculatedC, 26.09%; H, 2.63%; N, 34.76%. FTIR: 2981.60 (weak), 2109.15 (strong),1678.88, 1598.80, 1571.47, 1463.18 (NO₂), 1446.89, 1332.20, 1275.28cm⁻¹. ¹H NMR: (DMSO-d₆), δ 5.08 (2H), 4.83 (2H), 4.02 (2H). ¹³C NMR:(DMSO-d₆), δ 169.098, 107.74, 59.84, 58.16. HPLC: >99.7% pure. SafetyData: ABL Impact: 64 cm; ABL Friction: 800 at 8 ft/sec; TC ESD,Unconfined 50%<0.5 Joules (no mass ignition on bulk test); SBAT Onset:314° F.

Example 9 Synthesis of N-Succinyl-3,3-Dinitroazetidine

A 100 ml, three-neck, round-bottomed flask was charged with 30 mL ofanhydrous dichloromethane and 5.0 grams oftert-butyl-3,3-dinitroazetidine (t-BuDNAZ) under nitrogen. 4.5 grams ofsuccinyl chloride was added followed by the addition of 0.5 mL of borontrifluoride etherate. The reaction mixture was heated to 50° C. andmonitored by NMR. The reaction mixture was poured slowly into ice andthen filtered. The brown solid was washed with 3×20 mL portions ofdichloromethane, dried with sodium sulfate and concentrated undervacuum. The solid was purified by flash column chromatography (10% ethylacetate/hexanes) to yield a pale white solid in 20% yield (mp: 190-192°C.). Analysis for C₇H₉N₃O₇. Found C, 33.93%; H, 3.63%; N: 19%.Calculated C, 34.02%; H, 3.67%; N, 17.00%. FTIR: 3004.44 (weak), 1644.78(strong), 1558.45, 1472.60, 1450.06, 1423.01, 1369.90, 1338.05, 1310.05,1260.99 cm⁻¹. ¹H NMR: (DMSO-d₆), δ 5.27 (2H), 4.85 (2H), 2.03 (4H).HPLC: >97%. Safety Data: ABL Impact: 64 cm; ABL Friction: 800 at 8ft/sec; TC ESD, Unconfined at 50%<0.26 Joules (no mass ignition at 8Joules). DSC Onset: 253.86° C.

Example 10 Synthesis of N-Fumaryl-3,3-Dinitroazetidine

A 100 ml, three-neck, round-bottomed flask was charged with 8.69 gramsof tert-butyl-3,3-dinitroazetidine (t-BuDNAZ) under nitrogen and 5 mL offumaryl chloride was added followed by the addition of 0.5 mL of borontrifluoride etherate at 0° C. for 2 hours. The reaction mixture wasmonitored by NMR. The thick paste was washed with methanol and thenpoured into ice water. The solid was filtered and washed with 200 mL ofwater and dried under vacuum, which afforded a pale yellow solid in 20%yield (mp: 240° C.). Analysis for C₇H₇N₃O₇. Found C, 34.9%; H, 3.2%; N,19.6%. Calculated C, 34.3%; H, 2.9%; N, 17.1%. FTIR: 3082.73 (weak),1664.79 (strong), 1577.69, 1430.19 (NO₂), 1366.92, 1274.30, 1231.24,1213.45 cm⁻¹. ¹H NMR: (DMSO-d₆), δ 5.88 (2H), 5.29 (2H), 4.90 (2H).HPLC: >96%. Safety Data: ABL Friction: 800 at 8 ft/sec, TC ESDUnconfined at 50%: 1.05 Joules (mass ignition on bulk test).

Example 11 Synthesis of N-Trifluoroacetyl-3,3-Dinitroazetidine

A 100 ml, three-neck round-bottomed flask was charged with 2.28 grams oftert-butyl-3,3-dinitroazetidine (t-BuDNAZ) under nitrogen. Ten mL oftrifluoroacetic anhydride was added followed by the addition of 0.3 mLof boron trifluoride etherate. The reaction mixture was heated to 50° C.and monitored by NMR. The reaction was concentrated under vacuum. Theresidual oil was washed with water. The residual oil was added to hothexanes and to afford 460 mg of white needles (mp: 70-71° C.). Analysisfor C₅H₄F₃N₃O₅. Found C, H, N. Calculated C, 24.70%; H, 1.66%; N,17.29%. FTIR: 2991 (weak), 1716, 1683.96, 1591.37, 1576.43 (NO₂),1165.92, 1134.12 cm⁻¹. ¹H NMR: (DMSO-d₆), δ 5.39 (2H), 5.04 (2H).HPLC: >96% pure. Safety Data: ABL Friction: 800 at 8 ft/sec; TC ESDUnconfined at 50%: >8 Joules. DSC Onset: 240.75° C.

Finally, it should be noted that there are alternative ways ofimplementing the present invention. Accordingly, the present embodimentsare to be considered as illustrative and not restrictive, and theinvention is not to be limited to the details given herein, but may bemodified within the scope and equivalents of the appended claims. Allpublications and patents cited herein are incorporated by reference.

All references and publications cited herein are incorporated byreference in their entirety.

1. A method of synthesizing N-(succinyl)-3,3-dinitroazetidine,comprising: reacting tert-butyl-3,3-dinitroazetidine (“t-BuDNAZ”), anacid catalyst, and succinyl chloride.
 2. The method of claim 1, furthercomprising filtering, washing, and drying a reaction product oft-BuDNAZ, the acid catalyst, and succinyl chloride to produceN-(succinyl)-3,3-dinitroazetidine.
 3. A method of synthesizingN-(fumaryl)-3,3-dinitroazetidine, comprising: reactingtert-butyl-3,3-dinitroazetidine (“t-BuDNAZ”), an acid catalyst, andfumaryl chloride.
 4. The method of claim 3, further comprisingfiltering, washing, and drying a reaction product of t-BuDNAZ, the acidcatalyst, and fumaryl chloride to produceN-(fumaryl)-3,3-dinitroazetidine.
 5. A method of synthesizingN-(trifluoroacetyl)-3,3-dinitroazetidine, comprising: reactingtert-butyl-3,3-dinitroazetidine (“t-BuDNAZ”), an acid catalyst, andtrifluoroacetic anhydride.
 6. The method of claim 1, wherein reactingtent-butyl-3,3-dinitroazetidine (“t-BuDNAZ”), an acid catalyst, andsuccinyl chloride comprises reacting t-BuDNAZ, boron trifluorideetherate, and succinyl chloride.
 7. The method of claim 2, whereinfiltering, washing, and drying a reaction product of t-BuDNAZ, the acidcatalyst, and succinyl chloride to produceN-(succinyl)-3,3-dinitroazetidine comprises washing the reaction productof t-BuDNAZ, the acid catalyst, and succinyl chloride withdichloromethane.
 8. The method of claim 3, wherein reactingtert-butyl-3,3-dinitroazetidine (“t-BuDNAZ”), an acid catalyst, andfumaryl chloride comprises reacting t-BuDNAZ, boron trifluorideetherate, and fumaryl chloride.
 9. The method of claim 4, whereinfiltering, washing, and drying a reaction product of t-BuDNAZ, the acidcatalyst, and fumaryl chloride to produceN-(fumaryl)-3,3-dinitroazetidine comprises washing the reaction productof t-BuDNAZ, the acid catalyst, and fumaryl chloride with water.
 10. Themethod of claim 5, wherein reacting tert-butyl-3,3-dinitroazetidine(“t-BuDNAZ”), an acid catalyst, and trifluoroacetic anhydride comprisesreacting t-BuDNAZ, boron trifluoride etherate, and trifluoroaceticanhydride.
 11. The method of claim 5, further comprising washing areaction product of t-BuDNAZ, the acid catalyst, and trifluoroaceticanhydride with water.